Pwm channels don't send uevents when exported, this change adds the
channels to a pwm class and set their device type to pwm_channel so
uevents are sent.
To do this properly, the device names need to change to uniquely
identify a channel. This change is from pwmN to pwmchipM:N
Signed-off-by: David Hsu <david...@google.com>
---
v2: Use parent name instead of chip->base for channel naming.
Documentation/pwm.txt | 6 ++++--
drivers/pwm/sysfs.c | 18 +++++++++++++-----
2 files changed, 17 insertions(+), 7 deletions(-)
diff --git a/Documentation/pwm.txt b/Documentation/pwm.txt
index 789b27c..8453435 100644
--- a/Documentation/pwm.txt
+++ b/Documentation/pwm.txt
@@ -80,9 +80,11 @@ unexport - Unexports a PWM channel from sysfs (write-only).
The PWM channels are numbered using a per-chip index from 0 to npwm-1.
-When a PWM channel is exported a pwmX directory will be created in the
+When a PWM channel is exported a pwmchipN:X directory will be created in the
pwmchipN directory it is associated with, where X is the number of the
-channel that was exported. The following properties will then be available:
+channel that was exported. It will also be exposed at /sys/class/pwm/ and
+can be identified by the pwm_channel device type.
+The following properties will then be available:
period - The total period of the PWM signal (read/write).
Value is in nanoseconds and is the sum of the active and inactive
diff --git a/drivers/pwm/sysfs.c b/drivers/pwm/sysfs.c
index 01695d4..cb2b376 100644
--- a/drivers/pwm/sysfs.c
+++ b/drivers/pwm/sysfs.c
@@ -23,6 +23,8 @@
#include <linux/kdev_t.h>
#include <linux/pwm.h>
+static struct class pwm_class;
+
struct pwm_export {
struct device child;
struct pwm_device *pwm;
@@ -222,6 +224,10 @@ static struct attribute *pwm_attrs[] = {
};
ATTRIBUTE_GROUPS(pwm);
+static const struct device_type pwm_channel_type = {
+ .name = "pwm_channel",
+};
+
static void pwm_export_release(struct device *child)
{
struct pwm_export *export = child_to_pwm_export(child);
@@ -248,9 +254,11 @@ static int pwm_export_child(struct device *parent, struct
pwm_device *pwm)
export->child.release = pwm_export_release;
export->child.parent = parent;
+ export->child.type = &pwm_channel_type;
export->child.devt = MKDEV(0, 0);
+ export->child.class = &pwm_class;
export->child.groups = pwm_groups;
- dev_set_name(&export->child, "pwm%u", pwm->hwpwm);
+ dev_set_name(&export->child, "%s:%u", dev_name(parent), pwm->hwpwm);
ret = device_register(&export->child);
if (ret) {
@@ -355,7 +363,6 @@ ATTRIBUTE_GROUPS(pwm_chip);
static struct class pwm_class = {
.name = "pwm",
.owner = THIS_MODULE,
- .dev_groups = pwm_chip_groups,
};
static int pwmchip_sysfs_match(struct device *parent, const void *data)
@@ -368,14 +375,15 @@ void pwmchip_sysfs_export(struct pwm_chip *chip)
struct device *parent;
/*
- * If device_create() fails the pwm_chip is still usable by
+ * If device_create_with_groups() fails the pwm_chip is still usable by
* the kernel its just not exported.
*/
- parent = device_create(&pwm_class, chip->dev, MKDEV(0, 0), chip,
+ parent = device_create_with_groups(&pwm_class, chip->dev, MKDEV(0, 0),
+ chip, pwm_chip_groups,
"pwmchip%d", chip->base);
if (IS_ERR(parent)) {
dev_warn(chip->dev,
- "device_create failed for pwm_chip sysfs export\n");
+ "device_create_with_groups failed for pwm_chip sysfs
export\n");
}
}
--
2.8.0.rc3.226.g39d4020
